Transdermal Estrogen in Women With Anorexia Nervosa

Transdermal Estrogen for the Treatment of Bone Loss in Women With Anorexia Nervosa

Randomized, placebo-controlled study investigating the use of physiologic, transdermal estrogen for low bone mass in adult women with anorexia nervosa.

Anorexia nervosa is a prevalent psychiatric with a lifetime prevalence of up to 2.2%. Among the many medical co-morbidities associated with anorexia nervosa, the most common is significant bone loss, which can persist despite weight recovery. Nearly 90% of women with anorexia nervosa have osteopenia and this low bone mass is associated with an increased fracture risk. Nearly 30% of women with anorexia nervosa report a history of a fracture and a prospective study demonstrated a 7-fold increased risk of fracture in women with anorexia nervosa compared to age-matched controls. Because anorexia nervosa is a chronic disease that can persist despite psychiatric and nutritional counseling, the bone loss and increased fracture risk can persist and lead to lifelong morbidity. Therefore, finding a treatment for bone loss associated with anorexia nervosa is of critical importance.

This 18-month randomized, placebo-controlled study will investigate in women (ages 20 to 45 years old) with anorexia nervosa whether treatment with transdermal estrogen replacement will increase bone mineral density (BMD).

Inclusion Criteria:

1. Female
2. 19-45 years of age
3. DSM-5 psychiatric criteria for anorexia nervosa
4. <85% of ideal body weight as defined by the 1983 Metropolitan Life Insurance Height and Weight Tables
5. Amenorrhea
6. T-score of < -1.0 at spine or hip

Exclusion Criteria:

1. Diseases known to affect bone metabolism, including untreated thyroid dysfunction, vitamin D deficiency, Cushing's syndrome, diabetes mellitus or renal insufficiency (eGFR < 60)
2. Personal history of venous or arterial clot
3. History of stroke or myocardial infarction
4. History of hypercoagulable disorder
5. Personal history or history of a first-degree relative with breast cancer
6. History of hereditary angioedema
7. Any medication known to affect bone metabolism, including systemic glucocorticoids within three months of the baseline visit, depot medroxyprogesterone within 6 months of the baseline visit, oral bisphosphonates within one year of the baseline visit or IV bisphosphonates within three years of the baseline visit
8. Bone fracture within the prior 12 months
9. Serum potassium < 3.0 meq/L, serum ALT > 3 times the upper limit of normal or Hemoglobin < 10 g/dL
10. Fasting serum triglyceride level > 150 mg/dL
11. Pregnant or breastfeeding (or desiring pregnancy within the next 18 months)
12. Active substance abuse
13. Elevated PTH level
14. 25-OH vitamin D level < 20 ng/mL
15. Low phosphorus level